Re: rescue bootable cd ???
On 10/02/07 03:43:56PM -0400, Douglas A. Tutty wrote: > On Tue, Oct 02, 2007 at 07:08:11AM -0500, helices wrote: > > > Unfortunately, both systems on which I experienced such calamity ran lvm > > over software raid 5. In fact, both systems ran lilo, not grub; and > > everything was under lvm, including root and boot. Under these > > circumstances, there is specific configuration information missing, and > > that prevents the debian install cd, and knoppix, from being able to > > read my disks ;< > > I thought that grub's support of LVM and any raid other than raid1 > wasn't either supported or ready for prime-time? > AFAIK there will never be any real RAID or LVM support in GRUB, it only sort of supports RAID1 because both volumes have the full filesystem on them. Jim. -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: rescue bootable cd ???
I suppose is possible to make an USB-flash bootable eable to assemble the raid/lvm in boot time ready to repair the faulty system, is n't it? the floppy equivalent just to bring up the old system, or work with it in a chroot... On 10/2/07, Lennart Sorensen <[EMAIL PROTECTED]> wrote: > On Tue, Oct 02, 2007 at 07:08:11AM -0500, helices wrote: > > Unfortunately, both systems on which I experienced such calamity ran lvm > > over software raid 5. In fact, both systems ran lilo, not grub; and > > everything was under lvm, including root and boot. Under these > > circumstances, there is specific configuration information missing, and > > that prevents the debian install cd, and knoppix, from being able to > > read my disks ;< > > > > When I started this thread, I was thinking about the olden days, when I > > (tried to remember to) ma[dk]e a boot floppy after each new kernel ;> > > Of course in those days you didn't run software raid5 and lvm either, so > perhaps that is why those boot disks worked in the first place. > > Nothing prevents you from assembling a raid using mdadm and scanning for > lvm volumes and bringing those up from a knoppix dvd. I have done it > and it can be done. Try not to screw up badly enough to need it, since > it is a bit of a pain. :) > > Just don't touch mdadm --create and you should be safe. You just want > to assemble the raid, and then find the PVs, bring up the VG and then > activate the volumes and mount the LVs. > > -- > Len Sorensen > > > -- > To UNSUBSCRIBE, email to [EMAIL PROTECTED] > with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED] > > -- Perhaps the depth of love can be calibrated by the number of different selves that are actively involved in a given relationship. Carl Sagan (Contact) Jaime Ochoa Malagón Integrated Technology Tel: (55) 52 54 26 10
Re: rescue bootable cd ???
On Tue, Oct 02, 2007 at 02:31:19PM -0500, C M Reinehr wrote: > > Unfortunately, both systems on which I experienced such calamity ran lvm > > over software raid 5. In fact, both systems ran lilo, not grub; and [snip] > You may still be able to access your hard disks with Knoppix. After booting > Knoppix you first must load the md driver & raid drivers: `modprobe raid5` > should do it. Then, use the mdadm command to query the raid information > written to the hard drives, i.e., `mdadm --detail /dev/sdx`. Once you think > you have the right configuration start your raid array with > `mdadm -A /dev/mdx /dev/sdy ...`. Finally, once your raid array is up & > running you can bring up lvm. Knoppix comes with a script called mdrun (IIRC), the only thing it doesn't do is modprobe the various raidX modules. So: $ modprobe raid5 $ mdrun is all you need to do to get raid5 to run on knoppix. Like you said lvm is simple to jumpstart (I guess there is a script fo this as well). The only thing knoppix failed to do for my raid5/lvm system was to restore grub, it segfaulted but a chroot to the systems root disk was enough to fix. -- When you do things right, people won't be sure you've done anything at all. Daniel Tryba -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: rescue bootable cd ???
On Tue, Oct 02, 2007 at 07:08:11AM -0500, helices wrote: > Unfortunately, both systems on which I experienced such calamity ran lvm > over software raid 5. In fact, both systems ran lilo, not grub; and > everything was under lvm, including root and boot. Under these > circumstances, there is specific configuration information missing, and > that prevents the debian install cd, and knoppix, from being able to > read my disks ;< > > When I started this thread, I was thinking about the olden days, when I > (tried to remember to) ma[dk]e a boot floppy after each new kernel ;> Of course in those days you didn't run software raid5 and lvm either, so perhaps that is why those boot disks worked in the first place. Nothing prevents you from assembling a raid using mdadm and scanning for lvm volumes and bringing those up from a knoppix dvd. I have done it and it can be done. Try not to screw up badly enough to need it, since it is a bit of a pain. :) Just don't touch mdadm --create and you should be safe. You just want to assemble the raid, and then find the PVs, bring up the VG and then activate the volumes and mount the LVs. -- Len Sorensen -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: rescue bootable cd ???
On Tue, Oct 02, 2007 at 07:08:11AM -0500, helices wrote: > Unfortunately, both systems on which I experienced such calamity ran lvm > over software raid 5. In fact, both systems ran lilo, not grub; and > everything was under lvm, including root and boot. Under these > circumstances, there is specific configuration information missing, and > that prevents the debian install cd, and knoppix, from being able to > read my disks ;< I thought that grub's support of LVM and any raid other than raid1 wasn't either supported or ready for prime-time? > > When I started this thread, I was thinking about the olden days, when I > (tried to remember to) ma[dk]e a boot floppy after each new kernel ;> Bootfloppies aren't an option due to the size of the kernel and ramdisks. Here's my suggestion: I hope you have good backups: reinstall, raid1 partition for /boot or if your drives are big enough anyway, just a 400 or 500 MB / on raid1. Put the same partition at the beginning of each of your drives and put them all into the raid1 array. That way, no single drive failure can cause failure of your /boot or / If you must use raid5 for the rest, OK, but since drives are cheap, I'd suggest raid1. Use LVM overtop of this second raid array, one LV for each of the standard partitions (/usr, /home/, /var, possibly /tmp [or use tmpfs for /tmp]). Use Grub. Install grub in the MBR of all drives. Manually put an entry in grub that looks to each drive in the raid1 array (with co-responding root= kernel option if / is on raid1 instead of LVM). In this way, any single drive failure will still allow a full boot. If you need the performance of raid0 across a raid1 (non /boot, preferably non / too), e.g. for /var or /home, make new LVs after install that do striping. Good luck, Doug. -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: rescue bootable cd ???
On Tuesday 02 October 2007 07:08, helices wrote: > * "Gudjon I. Gudjonsson" <[EMAIL PROTECTED]> [2007:10:02:05:20:25+0200] scribed: > > Hi > >It is also possible to use the install disk. You just stop after > > detecting the hard disk (don't reformat it :) Then you do: > > #mkdir /mnt > > #mount /dev/sda1 /mnt > > #chroot /mnt > > and then you can do whatever you need to fix your system. > > > > Hope it helps > > Gudjon > > Unfortunately, both systems on which I experienced such calamity ran lvm > over software raid 5. In fact, both systems ran lilo, not grub; and > everything was under lvm, including root and boot. Under these > circumstances, there is specific configuration information missing, and > that prevents the debian install cd, and knoppix, from being able to > read my disks ;< > > When I started this thread, I was thinking about the olden days, when I > (tried to remember to) ma[dk]e a boot floppy after each new kernel ;> > > Any other ideas? You may still be able to access your hard disks with Knoppix. After booting Knoppix you first must load the md driver & raid drivers: `modprobe raid5` should do it. Then, use the mdadm command to query the raid information written to the hard drives, i.e., `mdadm --detail /dev/sdx`. Once you think you have the right configuration start your raid array with `mdadm -A /dev/mdx /dev/sdy ...`. Finally, once your raid array is up & running you can bring up lvm. Again, learn your configuration with pvdisplay, vgdisplay & lvdisplay. Then, make your logical volumes active with `lvchange -ay vgx/lvx ...` Once your logical volumes are active you can mount them, i.e., `mount -t ext3 /dev/vg0/lv_root /mnt`. Of course, use whatever details are appropriate for your system. Good luck! cmr -- Debian 'Etch' - Registered Linux User #241964 "More laws, less justice." -- Marcus Tullius Ciceroca, 42 BC -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: rescue bootable cd ???
* "Gudjon I. Gudjonsson" <[EMAIL PROTECTED]> [2007:10:02:05:20:25+0200] scribed: > Hi >It is also possible to use the install disk. You just stop after > detecting the hard disk (don't reformat it :) Then you do: > #mkdir /mnt > #mount /dev/sda1 /mnt > #chroot /mnt > and then you can do whatever you need to fix your system. > > Hope it helps > Gudjon Unfortunately, both systems on which I experienced such calamity ran lvm over software raid 5. In fact, both systems ran lilo, not grub; and everything was under lvm, including root and boot. Under these circumstances, there is specific configuration information missing, and that prevents the debian install cd, and knoppix, from being able to read my disks ;< When I started this thread, I was thinking about the olden days, when I (tried to remember to) ma[dk]e a boot floppy after each new kernel ;> Any other ideas? -- Best Regards, helices - Dare to fix things before they break . . . - Our capacity for understanding is inversely proportional to how much we think we know. The more I know, the more I know I don't know . . . -- signature.asc Description: Digital signature
Re: rescue bootable cd ???
On Monday 01 October 2007 23:13, Jim Crilly wrote: > On 10/01/07 05:15:27PM -0500, C M Reinehr wrote: > > I've seen the term before but don't understand exactly what COW means, > > but I think I know what you're talking about. I had a failing disk drive > > last Friday and had to boot my system off of a Knoppix disk to see what I > > could salvage from my raid-1 array. Knoppix didn't seem to include the > > smartmontools package but I was able to use apt-get to install it on the > > fly and use it to diagnose which disk was failing. > > COW stands for copy on write, whenever a change is made to a block (or > file maybe, I don't know what granularity unionfs uses) that block is > copied somewhere else and the original left in place so that the update > can succeed and the original still exists. Sort of like an LVM snapshot > only instead of being backed by a LVM volume the changes are only stored in > memory. > > But yea, the short answer is that it allows you to make changes and install > software on read-only medium like CDs. =) > > Jim. Thanks, Jim! :-) -- Debian 'Etch' - Registered Linux User #241964 "More laws, less justice." -- Marcus Tullius Ciceroca, 42 BC -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: rescue bootable cd ???
On 10/01/07 05:15:27PM -0500, C M Reinehr wrote: > I've seen the term before but don't understand exactly what COW means, but I > think I know what you're talking about. I had a failing disk drive last > Friday and had to boot my system off of a Knoppix disk to see what I could > salvage from my raid-1 array. Knoppix didn't seem to include the > smartmontools package but I was able to use apt-get to install it on the fly > and use it to diagnose which disk was failing. > COW stands for copy on write, whenever a change is made to a block (or file maybe, I don't know what granularity unionfs uses) that block is copied somewhere else and the original left in place so that the update can succeed and the original still exists. Sort of like an LVM snapshot only instead of being backed by a LVM volume the changes are only stored in memory. But yea, the short answer is that it allows you to make changes and install software on read-only medium like CDs. =) Jim. -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: rescue bootable cd ???
Hi It is also possible to use the install disk. You just stop after detecting the hard disk (don't reformat it :) Then you do: #mkdir /mnt #mount /dev/sda1 /mnt #chroot /mnt and then you can do whatever you need to fix your system. Hope it helps Gudjon -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: rescue bootable cd ???
On Monday 01 October 2007 17:44, Jaime Ochoa Malagón wrote: > http://wiki.debian.org/LiveCD Yes, that's where I have seen the term before, but I've been too lazy & too short of time to seriously consider it. I've been playing with Debian Live in my spare time for the past couple of months. Cheers! cmr > On 10/1/07, C M Reinehr <[EMAIL PROTECTED]> wrote: > > On Monday 01 October 2007 16:41, Jim Crilly wrote: > > > On 09/28/07 05:26:27PM -0500, helices wrote: > > > > What do you do? > > > > > > The last few times I need to rescue something I used an Ubuntu disc > > > that I had laying around, it doesn't include LVM but it uses a > > > copy-on-write unionfs so that you can install packages onto the running > > > LiveCD. Of course they're lost on reboot, but with a fast Internet > > > connection that doesn't really matter. > > > > > > I would be surprised if Knoppix didn't already have similar > > > functionality. > > > > > > Jim. > > > > I've seen the term before but don't understand exactly what COW means, > > but I think I know what you're talking about. I had a failing disk drive > > last Friday and had to boot my system off of a Knoppix disk to see what I > > could salvage from my raid-1 array. Knoppix didn't seem to include the > > smartmontools package but I was able to use apt-get to install it on the > > fly and use it to diagnose which disk was failing. > > > > Cheers! > > > > cmr > > -- > > Debian 'Etch' - Registered Linux User #241964 > > > > "More laws, less justice." -- Marcus Tullius Ciceroca, 42 BC > > > > > > -- > > To UNSUBSCRIBE, email to [EMAIL PROTECTED] > > with a subject of "unsubscribe". Trouble? Contact > > [EMAIL PROTECTED] -- Debian 'Etch' - Registered Linux User #241964 "More laws, less justice." -- Marcus Tullius Ciceroca, 42 BC
Re: rescue bootable cd ???
http://wiki.debian.org/LiveCD On 10/1/07, C M Reinehr <[EMAIL PROTECTED]> wrote: > On Monday 01 October 2007 16:41, Jim Crilly wrote: > > On 09/28/07 05:26:27PM -0500, helices wrote: > > > What do you do? > > > > The last few times I need to rescue something I used an Ubuntu disc that I > > had laying around, it doesn't include LVM but it uses a copy-on-write > > unionfs so that you can install packages onto the running LiveCD. Of course > > they're lost on reboot, but with a fast Internet connection that doesn't > > really matter. > > > > I would be surprised if Knoppix didn't already have similar functionality. > > > > Jim. > > I've seen the term before but don't understand exactly what COW means, but I > think I know what you're talking about. I had a failing disk drive last > Friday and had to boot my system off of a Knoppix disk to see what I could > salvage from my raid-1 array. Knoppix didn't seem to include the > smartmontools package but I was able to use apt-get to install it on the fly > and use it to diagnose which disk was failing. > > Cheers! > > cmr > -- > Debian 'Etch' - Registered Linux User #241964 > > "More laws, less justice." -- Marcus Tullius Ciceroca, 42 BC > > > -- > To UNSUBSCRIBE, email to [EMAIL PROTECTED] > with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED] > > -- Perhaps the depth of love can be calibrated by the number of different selves that are actively involved in a given relationship. Carl Sagan (Contact) Jaime Ochoa Malagón Integrated Technology Tel: (55) 52 54 26 10
Re: rescue bootable cd ???
On Monday 01 October 2007 16:41, Jim Crilly wrote: > On 09/28/07 05:26:27PM -0500, helices wrote: > > What do you do? > > The last few times I need to rescue something I used an Ubuntu disc that I > had laying around, it doesn't include LVM but it uses a copy-on-write > unionfs so that you can install packages onto the running LiveCD. Of course > they're lost on reboot, but with a fast Internet connection that doesn't > really matter. > > I would be surprised if Knoppix didn't already have similar functionality. > > Jim. I've seen the term before but don't understand exactly what COW means, but I think I know what you're talking about. I had a failing disk drive last Friday and had to boot my system off of a Knoppix disk to see what I could salvage from my raid-1 array. Knoppix didn't seem to include the smartmontools package but I was able to use apt-get to install it on the fly and use it to diagnose which disk was failing. Cheers! cmr -- Debian 'Etch' - Registered Linux User #241964 "More laws, less justice." -- Marcus Tullius Ciceroca, 42 BC -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: rescue bootable cd ???
On 09/28/07 05:26:27PM -0500, helices wrote: > What do you do? > The last few times I need to rescue something I used an Ubuntu disc that I had laying around, it doesn't include LVM but it uses a copy-on-write unionfs so that you can install packages onto the running LiveCD. Of course they're lost on reboot, but with a fast Internet connection that doesn't really matter. I would be surprised if Knoppix didn't already have similar functionality. Jim. -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: rescue bootable cd ???
On Friday 28 September 2007 17:26, helices wrote: > I have several rather complex debian systems, including software raid 5 > and lvm, &c. > > Occasionally, in the past, I have upgraded a debian system, after which > it no longer boots successfully. Unfortunately, for these complex > systems, neither the install/boot media, nor knoppix, result in access > to the files necessary to recover these systems. > > So, going forward, I want to incorporate generation of bootable rescue > cd's into my upgrade processes. Clearly, such a cd will exactly > duplicate my last successful boot, and give access to ALL files and > filesystems. > > [1] What is the simplest & most reliable process for creating such a cd? > > [2] Upgrading WHICH packages should be followed by creating such cd? > Obviously, upgrading vim itself is NOT likely to jeopardize my next > boot; but, the kernel, some libraries, and some packages involved in the > early boot stages, are possible culprits. > > What do you do? > > What do you think? It's very easy to create a GRUB boot floppy or CD. Just read the Installation section at: http://www.gnu.org/software/grub/manual/html_node/index.html At a minimum you are likely to need to update GRUB whenever you upgrade or install a new kernel, repartition, or add/change drives. Also, in an emergency there is a 64-bit version of Knoppix at http://www.applia.fr/contents/knoppix64.html that might come in handy. Cheers! cmr cmr -- Debian 'Etch' - Registered Linux User #241964 "More laws, less justice." -- Marcus Tullius Ciceroca, 42 BC -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
rescue bootable cd ???
I have several rather complex debian systems, including software raid 5 and lvm, &c. Occasionally, in the past, I have upgraded a debian system, after which it no longer boots successfully. Unfortunately, for these complex systems, neither the install/boot media, nor knoppix, result in access to the files necessary to recover these systems. So, going forward, I want to incorporate generation of bootable rescue cd's into my upgrade processes. Clearly, such a cd will exactly duplicate my last successful boot, and give access to ALL files and filesystems. [1] What is the simplest & most reliable process for creating such a cd? [2] Upgrading WHICH packages should be followed by creating such cd? Obviously, upgrading vim itself is NOT likely to jeopardize my next boot; but, the kernel, some libraries, and some packages involved in the early boot stages, are possible culprits. What do you do? What do you think? -- Best Regards, helices - Dare to fix things before they break . . . - Our capacity for understanding is inversely proportional to how much we think we know. The more I know, the more I know I don't know . . . -- signature.asc Description: Digital signature
